Brian,
To make sure everything is aligned: Date on my Pi is: Tue 29 Jan 07:57:34 UTC 2019
My timezone is +2.
Just in case I downloaded the log and made sure āauto refreshā is ticked
I will now go to Login URL and log in. That action immediately through the error Notices:
Screen shot below:
No new entries on screen!
I will download the log and compare with the log I downloaded before invoking the error screen.

Log file content:
2019-01-27 19:43:58.072|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:03.127|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:08.175|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:13.232|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:18.289|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:23.338|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:28.390|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:33.452|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:38.504|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:43.554|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:48.610|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:53.682|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:44:58.736|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:03.798|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:08.859|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:13.910|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:18.964|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:24.035|ERROR|input_controller.php|{"success": false, "message": "Format error, json value is not numeric"} for User: 1
2019-01-27 19:45:29.120|ERROR|index.php|Invalid API key 'ddbedfc879087d9ef85e5b51f9e67235'
2019-01-27 19:45:29.140|ERROR|index.php|Invalid API key 'ddbedfc879087d9ef85e5b51f9e67235'
2019-01-27 19:45:29.162|ERROR|index.php|Invalid API key 'ddbedfc879087d9ef85e5b51f9e67235'
Sorry!!
That does not really help.
Brian: I do not know where to find the :settings.php file"
Is this directly on the Pi using SSH or is that somewhere in the menu structure. MAYBE it is high up on a page and hidden behind the blue comments.
Sorry!
I have internet speed issue at the moment, but once sorted you are welcome to skype / VNC / TeamViewer to my PC and to take control so you can investigate quicker.
Regards
Frits